Obama: Russia plan for Syria chem arms may be 'positive'

US President Barack Obama said Monday that a Russian plan for Syria to hand over its chemical weapons was "potentially positive" and pledged to take it seriously.

But, in a CNN interview, Obama warned against any stalling tactics from Syria, and said the fact there was any talk of a diplomatic way out of the crisis was only down to his administration's threats of military action.

"It is a potentially positive development," Obama said of the Russian plan, as he gave interviews to six television anchors as part of a fierce push to win backing from Congress on strikes against Syria.

"I have to say that it's unlikely we would have arrived at that point where there were even public statements like that without a credible military threat," Obama told CNN.

The president said he had asked his Secretary of State John Kerry to work with Russia to see if Moscow's suggestion of a deal, which would see Syrian chemical weapons placed under international supervision, was possible.

"This is a continuation of conversations I've had with President Putin for quite some time," Obama told PBS, and told Fox he had first discussed the idea with Russian President Vladimir Putin at last year's G20 summit in Mexico.

"If we can exhaust these diplomatic efforts and come up with a formula that gives the international community a verifiable, enforceable mechanism to deal with these chemical weapons in Syria, then I'm all for it."

Obama admitted in another interview with NBC News that he was not yet certain that he would win congressional backing for a new US military venture in the Middle East.

"I wouldn't say I'm confident," Obama said.

"I'm confident that the members of Congress are taking this issue very seriously and they're doing their homework and I appreciate that."

The president said that though the Russian plan could turn into a "significant breakthrough" on the crisis, he believed that caution was merited, simply because of the track record of President Bashar al-Assad's regime.

"We have to be skeptical because this is not how we've seen them operate-- over the last couple of years," Obama said.

The president told ABC News that any deal that could be verified to take Syria's chemical weapons off the battlefield could "absolutely" head off the prospects of US missile strikes to punish an August 21 chemical weapons attack.

Obama also suggested that eventual US strikes against Syria could be delayed by a combination of the new developments and still soft US public opinion on the idea of launching military action in Syria.

"We're going to have time to have a good deliberation in Congress," Obama told Fox television.

"We will pursue this diplomatic track. I fervently hope that this can be resolved in a non-military way.

"But I think it is important for us not to let the, you know, the pedal off the metal when it comes to making sure that they understand that we mean what we say about these international bans on chemical weapons."